Registration of ‘MiniMax’ Soybean

Journal of Plant Registrations, Vol. 1, No. 2, September 2007 97 ‘M iniMax’ soybean [Glycine max (L.) Merr.] (Reg. No. CV-489, PI 643148) was developed by the USDA-ARS at Beltsville, MD. It was released on April 13, 2006 because of its small stature, early maturity date, and small seed size, to allow more plants to be grown and to mature in a smaller space than other soybean cultivars (Fig. 1). It is intended for researchers with limited space who desire high-density planting and as a basic laboratory model for soybean genomics, biochemical, plant disease and physiological studies. MiniMax is derived from an F9 plant from the cross [‘AC Colombe’ × PI548240 (‘T263’)] × PI548650 ‘Nattosan’. AC Colombe is a cultivar developed for the Asian natto soyfood market (Cober et al., 2001). Nattosan was developed at the Eastern Cereal and Oilseed Research Centre, Agriculture and Agri-Food Canada, Ottawa, Ontario Canada (Zarkadas et al., 1997). AC Colombe and Nattosan are Maturity Group 00, while T263 is Maturity Group I and is a donor of df5df5 (Palmer 1977, 1984). The cross from which MiniMax originated was made in the summer of 1998 at Beltsville, MD. MiniMax was advanced by pedigree inbreeding with selection for early maturity, small stature, and small seed size in the fi eld and greenhouse at Beltsville, MD. MiniMax was planted in the fi eld June fi rst at Beltsville, MD (approx. 39° North latitude) matured in 73 to 85 d with an average plant height of 22 cm. Plants were also grown in the greenhouse in 16 h light/8 h dark for the fi rst 16 d, then at 12 h light/12h dark to initiate fl owering, which began at 23 to 27 d. The temperature was maintained between 72 and 80o F during the day and 72 to 75o F at night. Natural greenhouse lighting was supplemented with sodium vapor lights during winter months. Dry brown pods can be harvested at 9 to 11 wk after planting. In the greenhouse the small seed averaged about 5.1 g/100−1 seeds and 14 seeds per plant in the summer. MiniMax has purple fl owers, brown pods, gray pubescence and produces seeds with a yellow seed coat and Registration of ‘MiniMax’ Soybean